The pipeline compensator is broken, and the whole pipeline has to be dismantled before it can be replaced. It is shut down for two days, resulting in a loss of more than 100,000 yuan. I asked him what compensator he used and he said it was a monolithic non-metallic expansion joint. I said: Then you might as well look at the split one.
Split non-metallic compensator, to put it bluntly, is to disassemble the band and frame of the traditional integral non-metallic expansion joint into independent modules. The loop belt is a circle of fabric layer (that is, we often call non-metallic expansion joint/fabric fiber expansion joint), the heat insulation layer is separate, and the sealing structure is also detachable. Well, monolithic, just like a can, if it breaks, you have to throw it whole. Split, like Lego, where it breaks, replace it.
Installation and maintenance do not need to dismantle pipelines, and the saved labor hours can be calculated
This point is most straightforward-the flange and frame of the split compensator are fixed to the pipe, and when replacing the ring belt or insulation, you just need to loosen the platen bolts, pull the old ring belt out, plug the new ring belt in, and tighten the bolts. No pipes, no flanges, no even brackets.
What about monolithic? You have to cut off the pipe, remove the entire expansion joint, replace it with a new one, and then re-weld the flange and align it. It takes at least two days to do a set of work. While the split replacement, journeymen can do it in half a day. Calculate an account: there are 4 people in a maintenance team, the labor cost is 3,000 yuan a day, and the total time for a whole replacement is 9,000 yuan in 3 days; Split type half day plus material fee, 2000 yuan capped. And what about discontinuation losses? Many flue gas pipelines and desulfurization systems will lose hundreds of thousands of capacity once they are stopped. Is that the truth?
The ring belt and the insulation layer are independent, and the resistance to high temperatures is doubled
The ring belt and insulation layer of the integral non-metallic expansion joint are bonded together. Under high temperature, the insulation material ages, and the ring belt suffers. The split type is different, and the loop (that is, the fabric fiber layer) and the internal insulation (such as a ceramic fiber blanket) are installed separately. The insulation layer is attached to the inside of the pipe, and the loop belt undertakes sealing and displacement compensation on the outside. There is an air layer in the middle of the two, which is equivalent to adding another heat dissipation barrier.
In the flue gas pipeline of power plants, the medium temperature often reaches above 600℃. Under the integral structure, once the insulation layer collapses, the heat is directly transferred to the ring belt, and the ring belt will be brittle in a few months. What about the split? The insulation can be replaced separately, and the band temperature is always below 150℃, which more than doubles the life span. We have measured that the maintenance period of split structure has been extended from 6 months to 18 months under the same working conditions.
The amount of compensation is large, but it is not stifling, and rectangular and round ones can be done
Another advantage of the split structure is the large amount of compensation. Because the ring belt is freely suspended from the frame, there is no integral welding stress like a monolithic one. It can increase the amount of compensation by layering multiple layers of fabric, single layer is not enough? Add another layer and it's very flexible.
And whether the pipe section is circular or rectangular, the split type can be done. For example, our common rectangular non-metallic expansion joint is used in flue and air duct, with a cross section of tens of square meters. To make the monolithic so big, the mold cost is frighteningly high, and the transportation and installation are also laborious. The split type can be assembled on site, the frame is transported to the site in sections, and the circle tape is hung like a curtain. Think about it, a rectangular expansion joint of 5 meters ×4 meters can't be transported in one piece, but a few split boxes can be done.
The seal structure is individually adjustable, and the air leakage rate is lower than you think
Many people are worried that the split will leak air. On the contrary, the split seal structure is independently designed and adjustable. Generally, multiple seals are used: thermal insulation sealing layer on the inside, airtight ring band on the outside, and adjustable pressing device between the two. If you find an air leak, you don't need to dismantle the equipment, just adjust the pressure plate bolts and increase the compression amount of the sealing ring.
What about monolithic? The sealing performance depends entirely on the quality of the bond at the time of leaving the factory. Once the bond is aged and cracked, you can't even mend it-you can only replace it with a new one. We have done comparative tests: under the same working conditions, the air leakage rate of split structure can be controlled below 0.5%, and the integral structure is generally between 1%-2%. For the working conditions of flue gas baffle door and desulfurization system, which have strict leakage requirements, this gap can determine whether the system can meet the emission standard.
If the single layer is broken, replace the single layer, and the whole one has to be thrown away-this account is clear
This is the most heart-wrenching comparison. Integral non-metallic expansion joint, even if only the outer layer of the ring belt is worn out by fly ash, you have to remove the whole expansion joint and scrap it, because the ring belt, the insulation layer and the frame are integrated and can't be replaced separately. A set of tens of thousands or even hundreds of thousands of things is completely wasted just because of a small hole.
What about the split? Circle straps can be replaced in layers. For example, multi-layer fabric structure, the outermost layer is worn, just replace the outer piece. Insulation collapsed? Pull out the insulation separately and replace it with a new one. The frame won't break after decades of use. Calculate an account: the initial purchase price of a split compensator may be 10%-15% more expensive than that of a monolithic compensator, but the maintenance cost is reduced by more than 60% over the whole life cycle. Moreover, your spare parts only need to save a few sets of ring belts and insulation layers, and you don't need to save the overall expansion joint assembly. The warehouse has less pressure and less capital occupation.
So you see, the five characteristics of the split non-metallic compensator-no dismantling of pipes, split insulation, large compensation flexibility, adjustable sealing, and layered replacement-each of them is calculating with the integral one. Especially for power stations, cement, desulfurization and chemical industries with many pipelines and poor working conditions, the time saved is profit. The next time you choose a model, don't just look at the quotation, but also include the maintenance costs for the next few years. You know what you know.